I looked up the coaster KingDa Ka and it said the G-Force was 5 Gs and I want to know if any number of gs is your weight multiplied by that number

Normally, when still, you are pressed against the Earth by a force corresponding to 1g (g=9.8m/s^2, so every kg of your mass is pulled by a force of 9.8N, so for a 100kg bloke it would be 980N).
With "5g" the force is then 5x more, so 5*9.8N per each kg of your weight (so nearly 5kN for that bloke).